Hello Pavan,

If the copper etch solution you're using is an isotropic etchant (which it
probably is), you're going to see undercutting because the etch proceeds
laterally as fast as it proceeds through the thickness of the foil.  To
achieve a vertical etch profile you'll need to use an anisotropic technique
such as RIE.

Good luck,

Brian C. Stahl
Graduate Student Researcher
UCSB Materials Research Laboratory
brian.stahl@gmail.com / bstahl@mrl.ucsb.edu
Cell: (805) 748-5839
Office: MRL 3117A


On Thu, May 7, 2009 at 10:59 AM, Feng-Yuan Zhang  wrote:

> Hi Pavan,
>
> You might want to check if the PR on the foil is treated properly and the
> foil is in good shape. Some more information can be found at J. Micromech.
> Microeng. 16 (2006), p. 23.
>
> Hope this helpful. Thanks,
>
> Fengyuan
>